Formed article of cellulose acetate treated with organic titanium chelate compounds

ABSTRACT

Anti-static characteristics for formed cellulose acetate articles are generated by incorporation into or on the article of an organic titanium chelate compound.

Haslam 117/144 X United States Patent [1 1 1111 3,808,038 Ueno et al. Apr. 30, 1974 [5 FORMED ARTICLE OF CELLULOSE 2,525,049 10/1950 Signaigo 117/144 x ACETATE TREATED WITH ORGANIC 2,658,000 1 1/1953 Sullivan et al. 1 17/144 X TITANIUM CHELATE Cob/[POUNDS 2,788,295 4/1957 Cooke et al. 1 17/144 X [75] Inventors: Wataru Ueno, Kanagawa; Hideo FOREIGN PATENTS OR APPLICATIONS Kawaguchi; Nobuhiko Minagawa, 557,905 5/1958 Canada 106/ 169 7 both of Sh1zu0ka, all of Japan OTHER PUBLICATIONS [73] ASSgnee: Fuji Photo Feld et al., The Organic Chemistry of Titanium, 1965,

Nakanuma, Japan pp. 58-68, 174-183. [22] Filed: Feb. 24, 1971 Hist, R. P., et al., Polyfunctional lsocyanatest Titanium Organics as Cross-Linking Agents for Cellulose [21] Appl' Derivatives, Ind. & Engr. Chemistry, vol. 48, N0. 8,

Aug., 1956, P. 1,325. [30] Foreign Application Priority Data Feb. 24, 1970 Japan 45-15706 Primary Examiner-William D. Martin Assistant Examiner-M. R. Lusignan [52] US. Cl 117/144, 106/ 169, 106/189, Attorney, Agent, or Firm-Sughrue, Rothwell, Mion,

106/196 Zinn & Macpeak [51] Int. Cl. C08j H38 [58] Field of Search 117/144, 159; 106/169,

106/196, 189 [57] ABSTRACT Anti-static characteristics for formed cellulose acetate 5 References Cited articles are generated by incorporation into or on the UNITED STATES PATENTS article of an organic titanium chelate compound.

2,768,909 10/1956 1 Claim, No Drawings FORMED ARTICLE OF CELL ULOSE ACETATE TREATED WITH ORGANIC TITANIUM CI-IELATE COMPOUNDS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an antistatic method for formed articles of cellulose acetate. More particularly, it is concerned with a method of preventing static troubles by adding an organic titanium chelate compound to cellulose acetate and then forming the article or by treating the surface of a formed article of cellulose acetate with a solution of an organic titanium chelate compound in an organic solvent.

2. Description of the Prior Art Some antistatic methods for plastics hitherto have been proposed, for example, by reducing the generation of static charges on the surface of the plastics due to friction or contact with another object, or lowering the electric resistance of the surface of plastics to increase the dissipation of the static charges. The latter method has been carried out completely.

We, the inventors, have conducted research on antistatic methods for formed articles of cellulose acetate for a long time and have invented the following antistatic method, which relates to the reducing of the generation of staticcharges on the surface.

SUMMARY OF THE INVENTION in whichR and R are alkyl groups of or 4 carbon atoms, R is a hydrogen atom, an alkyl group of from 1 to 4'carbon atoms, or an aryl group of from 6 to 10 carbon atoms, R R and R are hydrogen atoms or alkyl groups of from 1 to 4 carbon atoms and R is an alkoxyl group of from 1 to 4 carbon atoms or an aryl group of from 6 to 10 carbon atoms, and General Forr'riulaB in which R and R are alkyl groups of 3 or 4 carbon atoms, R is an alkyl group of from 1 to 4 carbon atoms or an aryl group of from 6 to 10 carbon atoms, R, is a hydrogen atom or an alkyl group of from 1 to 4 carbon atoms, R is an alkyl group of from 1 to 4 carbon atoms, an aryl group of from 6 to 10 carbon atoms, or an alkoxyl group of from 1 to 4 carbon atoms.

The titanium chelate compounds can be obtained by reacting a titanium alkoxide with at least one of the keto-alcohols, aldehyde-alcohols and dicarbonyl compounds having an active hydrogen.

DETAILED DESCRIPTION OF THE INVENTION The organic titanium chelate compound used in the invention reacts with the hydroxyl groups remaining in the cellulose acetate forming a strong chemical bond. Therefore, it is not removed by friction or water washing and the antistatic effect does not deteriorate with the passage of time.

A titanium alkoxide obtained by reacting titanium tetrachloride with a monohydric alcohol is too reactive to be stable. For example, it is immediately converted into titanium dioxide by a microamount of water in a solvent or by the moisture in the air. On the contrary, the organic titanium chelate compound of the invention is so stable that it does not require a particularly dehydrated solvent and is not changed when left in the air.

I The organic titanium chelate compound of the invention can be obtained by reacting a titanium alkoxide with one or more organic compounds capable of forming the chelate compound, such as aldehyde-alcohols, keto-alcohols and dicarbonyl compounds having active hydrogens. Suitable titanium alkoxides which can be used, for example, are tetraisopropyl titanate and tetrabutyl titanate. A suitable aldehyde-alcohol which can be used is B-hydroxybutyraldehyde and suitable ketoalcohols which can be used are diacetone alcohol and 'y-ketobutanol. The titanium alkoxide is reacted with the aldehyde alcohol and/or keto alcohol thus obtaining the above-described organic titanium chelate compound having the General Formula A.

Examples of the dicarbonyl compounds having active hydrogens which can be used are acetylacetone, acetoacetic acid ester, benzoylacetone and benzoylacetic acid ester. The titanium alkoxide is reacted with the dicarbonyl compound having an active hydrogen thus obtaining the above-described organic titanium chelate compound having the General Formula B.

In the antistatic method of the invention, these compounds may be added to the cellulose acetate which is formed into pellets followed by molding or may be applied in the form of a solution, dispersion or emulsion to the surface of a formed article of cellulose acetate.

The invention utilizes the fact that the static generating property of cellulose acetate can be varied by adding an organ ic titanium chelate compound to or coating an organic titanium chelate compound onto a surface. Static charge can be suppressed while the static generating characteristics are varied appropriately depending on the quantity of the organic titanium chelate compound added or coated. Therefore, it is advantageous in that the quantity of the organic titanium chelate compound used can be varied freely so as to reduce the magnitude of the static generation depending on the kind of objects which will be subjected to friction or which may come into contact with other objects.

ln accordance with the method of this invention, the disadvantages encountered with the prior art method wherein the surface electric resistance of the formed article to be treated is lowered by a surfactant can be overcome, that is, that the treated layer on the surface is readily stripped off by friction or removed by water washing or the antistatic agent exudes on the surface. When a formed article is treated according to the invention, the static charge can be prevented permanently without deteriorating the quality of the formed article.

The following examples are given to illustrate the invention in greater detail without limiting the scope of the invention.

EXAMPLE 1 H: C O O i l-CH:

The organic titanium chelate compound having the above-described structural formula, synthesized from tetrabutyl titanate and diacetone alcohol, was added to cellulose acetate (acetic acid bonded 60.7 percent) using the following procedure. 25 g of cellulose acetate (acetic acid bonded 60.7 percent) was dissolved in a mixed solvent consisting of 18 g of n-butanol and 207 g of methylene chloride. After the dissolving was completed, 0.25 g of the above-described organic titanium chelate compound was dissolved in g of methylene chloride, added and mixed with adequate agitation. The composition of the resulting solution corresponded to 1.0 g of organic titanium chelate compound/100 g of cellulose acetate. Where it is desired to vary the content of the organic titanium chelate compound, the concentration of the organic titanium chelate compound in methylene chloride solution can be varied while holding constant the ratio of the cellulose acetate and each solvent.

The foregoing cellulose acetate solution was at room temperature flowed, spread and dried. The resulting film was stripped from a support and held at 1 10C for 2 hours to remove the residual solvent. The charge on frictional contact with a rubber roller and the surface electric resistivity of the thus obtained cellulose acetate film are shown in Table l, at a relative humidity of 65 percent. The amount of the organic titanium chelate compound added to the cellulose acetate (acetic acid bonded 60.7 percent) was adjusted to 0.7 g/l00 g cellulose acetate thereby completely preventing the friction charge with rubber.

TABLE 1 Amount of Organic EXAMPLE 2 ll C() 02115 TABLE 2 Amount of Organic Titanium Chelate Surface Compound Added Charge on Frictional Electric (g/IUO g cellulose Contact with Rubber Resistiv|ty acetate) Roller (V) ((1) 0.0 +29 1.3 10" 0.25 +13 7.5 X 10'" 0.50 2 7.4 X 10' L0 6 7 2 X10121 6 9.4 x 10" As is evident from these results, the added amount of 0.5 g/ g cellulose acetate is effective so as to reduce the charge on frictional contact with rubber roller.

EXAMPLE 3 1.75 g of the organic titanium chelate compound having the above-described structural formula, synthesized from tetraisopropyl titanate and benzoylacetophenone, was dissolved in a mixed solvent consisting of 100 g of methylene chloride, 200 g of methyl ethyl ketone and 50 g of isopropanol, coated onto a film of cellulose acetate (acetic acid bonded 55.0 percent) and dried at C for 5 minutes. The composition of the resulting coating solution corresponded to a concentration of the organic titanium chelate compound of 0.5 percent by weight. Where it is desired to vary the concentration of the coating solution, the amount of the organic titanium chelate compound can be varied while holding the composition and amount of the solvent constant. Coating and drying conditions are also constant.

The charge on frictional contact with a rubber roller and the surface electric resistivity of the thus treated film were measured at a relative humidity of 65 percent to obtain the results shown in Table 3.

As is evident from these results, a concentration of about 0.5 percent is effective to prevent a charge on frictional contact with a rubber roller.

EXAMPLE 4 The organic titanium chelate compound, synthesized from tetrabutyl titanate and B-hydroxybutyraldehyde, was added to a film of cellulose acetate (acetic acid bonded 55.0 percent) in a manner similar to that of Example 1. The charge on frictional contact with a rubber roller and the surface electric resistivity were measured at a relative humidity of 65 percent, with the results obtained being shown in Table 4.

TABLE 4 Amount of Organic The organic titanium chelate compound synthesized from tetraisopropyl titanate and acetylacetone was coated onto a film of cellulose acetate (acetic acid bonded 60.7 percent) using the same procedure as described in Example 3 and the charge on frictional contact with a rubber roller and the surface electric resistivity were measuredat a relative humidity of 65 percent with the results obtained being shown in Table 5.

TABLE 5 Surface Concentration of Charge on Frictional Electric Coating Solution Contact with Rubber Resistivity (wt Roller (V) (O) 0.0 l' 28 4.5 X 0.5 4 8.9 X 10' 1.0 e 6 9.0 X 10' 2.0 5 7.5 X 10" What is claimed is:

l. A cellulose acetate article having anti-static characteristics comprising cellulose acetate having coated thereon or incorporated therein an anti-statically effective amount of an organic titanium chelate compound selected from the group consisting of titanium chelate compounds having the general formula A:

General Formula A wherein R, and R are alkyl groups of 4 carbon atoms, R is selected from the group consisting of a hydrogen atom, an alkyl group of from 1 to 4 carbon atoms, and an aryl group of from 6 to 10 carbon atoms, R R and R are selected from the group consisting of hydrogen atoms and alkyl groups of from 1 to 4 carbon atoms, and R is selected from the group consisting of an alkoxyl group of from 1 to 4 carbon atoms and an aryl group of from 6 to 10 carbon atoms, and having the general formula B:

General Formula B wherein R and R are alkyl groups of 4 carbon atoms, R is selected from the group consisting of an alkyl group of from 1 to 4 carbon atoms and an aryl group of from 6 to 10 carbon atoms, R, is selectedfromthe group consisting of a hydrogen atom and an alkyl group of from 1 to 4 carbon atoms and R is selected from the group consisting of an alkyl group of from 1 to 4 carbon atoms, an aryl group of from 6 to 10 carbon atoms, and

an alkoxyl group of from 1 to 4 carbon atoms. 

